1. Field of the Invention
The present invention relates to stereoscopic picture obtaining devices, and more specifically to a stereoscopic picture obtaining device for obtaining two stereoscopic pictures having parallax.
2. Description of the Background Art
A method in which two cameras simultaneously shoot the same subject from different locations of viewpoint to measure the three-dimensional position of the subject based on parallax information of two shot pictures has been known (hereinafter referred to as first background art). An exemplary method of this type is described in xe2x80x9cImage of 3D Space-Mathematical Geometryxe2x80x9d, pp. 142-143, Koichiro Deguchi, published by Shokodo, May, 19941 (ISBN4-7856-2125-7C3355).
Japanese Patent Laying-Open No. 7-248212 discloses a method of obtaining a stereoscopic picture including parallax information using a single camera (hereinafter referred to as second background art). A three-dimensional shape measuring device according to the second background art is structured so that four mirrors are provided in front of a camera, simultaneously capturing a left picture from a left viewpoint and a right picture from a right viewpoint, and the obtained left and right pictures are entered into left-half and right-half fields of view, respectively, of the single camera.
The above first background art obtains a stereoscopic picture using two cameras and, therefore, requires two picture systems, resulting in a large system structure and high costs.
On the other hand, in the above second background art, the field of view of the single camera is divided into halves, a left-half and a right-half, and these two fields of view after division independently capture left and right pictures. Therefore, the angle of view when the subject is viewed from one of the fields of view after division becomes half the angle of view when viewed from the entire field of view of the camera. This will be described more specifically referring to FIG. 11. Assuming that the picture size of the entire field of view in the camera is, for example, 640*480 pixels, a left picture and a right picture when shot in full size are represented by a left picture 1101 and a right picture 1102 in FIG. 11. However, these left and right pictures 1101 and 1102 are too large to be stored as they are, in the left and right fields of view, respectively. Therefore, portions of the left picture 1101 in areas b and c (320*480 pixels) are stored in the left field of view of the camera, and portions of the right picture 1102 in areas f and g (320*480 pixels) are stored in the right field of view of the camera. That is, the effective fields of view in the lateral direction of the left and right pictures 1101 and 1102 are halved. As a result, pictures of peripheral parts a and d of the left picture 1101 and pictures of peripheral parts e and h of the right picture 1102 are disadvantageously eliminated. This does not allow parallax information of the whole subject to be obtained, causing difficulty of measuring the three-dimensional position.
Therefore, an object of the present invention is to provide a stereoscopic picture obtaining device capable of obtaining a single stereoscopic picture having parallax from two pictures with a wide effective field of view.
The present invention has the following various features to achieve the object above.
A first aspect of the present invention is directed to a stereoscopic picture obtaining device for obtaining a stereoscopic picture with parallax by a single camera. The device comprises two objective lenses for simultaneously obtaining two pictures of a subject from different locations of viewpoint, picture merge means for merging the two pictures obtained by the two objective lenses into a single picture through an optical operation, picture reducing means for reducing the single picture after synthesis by the picture merge means at a predetermined reduction ratio and projecting a picture onto a predetermined projection plane, and an image pickup device for converting the picture projected onto a pickup plane which is arranged on the projection plane into image data.
As described above, in the first aspect, two pictures of a subject obtained by the two objective lenses from different locations of viewpoint are merged into a single picture, and then reduced to be projected onto the image pickup device. It is therefore possible to obtain a single stereoscopic picture with parallax without narrowing the effective fields of view of the two pictures.
According to a second aspect, in the first aspect, the stereoscopic picture obtaining device further comprises, in any position of order of the objective lenses through the image pickup device, picture rotating means for rotating the picture or pictures through optical operation. As described above, in the second aspect, when two stereoscopic pictures do not fit well into the pickup plane of the image pickup device, it is possible to correct the relation in position between two pictures by rotation.
According to a third aspect, in the second aspect, the picture rotating means rotates the two pictures obtained by the two objective lenses before synthesis by the picture merge means, and the picture merge means merges the two pictures rotated by the picture rotating means into a single picture.
According to a fourth aspect, in the second aspect, the picture rotating means rotates the picture after synthesis by the picture merge means.
According to a fifth aspect, in the second aspect, the picture rotating means rotates the picture or pictures 90 degrees.
According to a sixth aspect, in the first aspect, the picture merge means arranges the two pictures obtained by the two objective lenses on right and left and generates a single merged picture.
According to a seventh aspect, in the first aspect, the picture merge means arranges the two pictures obtained by the two objective lenses on top and bottom and generates a single merged picture.
According to an eighth aspect, in the first aspect, the stereoscopic picture obtaining device further comprises aspect ratio changing means for reducing/enlarging the two pictures obtained by the two objective lenses through optical operation before synthesis by the picture merge means, thereby changing an aspect ratio of each of the two pictures. As described above, in the eighth aspect, by changing each aspect ratio of the two pictures obtained by the two objective lenses, it is possible to almost completely match the size of the merged picture after reduction with the size of the pickup plane of the image pickup device.
A ninth aspect is directed to a stereoscopic picture obtaining device for obtaining a stereoscopic picture with parallax. The device comprises two image taking means for shooting a subject from different locations of viewpoint and generating two sets of image data having parallax, image merge means for merging the two sets of image data generated by the two image taking means into a single set of image data through electrical operation, image reducing means for reducing the single set of image data after synthesis by the image merge means at a predetermined reduction ratio through electrical operation, and storage means for storing image data after reduction by the image reducing means.
As described above, in the ninth aspect, two sets of image data having parallax, generated by two image taking means, are merged into a single set of image data, and then reduced to be stored in the storage means. It is therefore possible to obtain a single set of image data having parallax without narrowing the effective fields of view of the two sets of image data, resulting in a small capacity of the storage device.
According to a tenth aspect, in the ninth aspect, the stereoscopic picture obtaining device further comprises, in any position of order of the image taking means through the storage means, image rotating means for rotating the image data through electrical operation.
As described above, in the tenth aspect, when the two sets of image data do not fit well into the frame size of the storage means, it is possible to correct the relation in positions between the image data by rotation.
According to an eleventh aspect, in the tenth aspect, the image rotating means rotates the two sets of image data generated by the two image taking means before synthesis by the image merge means, and the image merge means merges the two sets of image data rotated by the image rotating means into a single set of image data.
According to a twelfth aspect, in the tenth aspect, the image rotating means rotates the image data after synthesis by the image merge means.
According to a thirteenth aspect, in the tenth aspect, the image rotating means rotates the image data 90 degrees.
According to a fourteenth aspect, in the ninth aspect, the image merge means arranges the two sets of image data generated by the two image taking means on right and left and generates a single set of image data.
According to a fifteenth aspect, in the ninth aspect, the image merge means arranges the two sets of image data generated by the two image taking means on top and bottom and generates a single set of image data.
According to a sixteenth aspect, in the ninth aspect, the image reducing means reduces the single set of image data after synthesis by the image merge means, thereby changing an aspect ratio of the single image data. As described above, in the sixteenth aspect, by changing the aspect ratio of the image data after synthesis by the image merge means, it is possible to almost completely match the size of the merged image after reduction with the frame size of the storage means.